Initial throttle hesitation -- lots of codes

[PapaVanTwee]

I have a 2006 Chevy Aveo Hatchback. When I bought it, I knew the previous owner didn't do much in maintenance on the car, so I had to do a few things. I did my first valve cover gasket change due to oil in the plug wells, got new tires, plugs and wires, etc. I keep the oil changed with synthetic now, as I drive about 1000 miles a week delivering car parts.

Recently, the transmission let go, and had to be rebuilt. I had the timing belt and tensioner changed. Some front suspension parts were changed, and I had a wheel bearing go on the driver side front that was replaced.

Recently with the onset of winter I've noticed a little hesitation at throttle tip in. The faster you floor it, the more of a hesitation you get. But after this initial hesitation, it seems fine otherwise. Gas mileage has hovered around 28mpg since I got it. I searched through this forum, and I have tried a couple things, including new plugs and wires again, and cleaning the throttle body (TB). Initially, I couldn't get the butterfly to open, even when I turned on the car and pressed in on the gas (with a broom). I didn't want to hurt it, but I now realize it takes a lot of pressure to open.

So, I went out to get codes today, since I wasn't feeling too lazy, and had some time. The codes are P2188, P0068, P2106, P2110, P0172, P0106, and P161B. After searching through the forums, TB cleaning seems to be the main issue. So back out with a screwdriver, soft tooth brush, and carb cleaner. and this time I forced it open, and my toothbrush turned practically black. I then inspected the hose going to the TB and saw a crack that could be causing the dirt issue. I'll be replacing that ASAP.

After cleaning the TB, I'm still getting the hesitation. Is it possible the TB is so gunked up it needs replaced? And is there anything else I should be looking at?

[Aveo5_boy]

I just recently had my throttle body replaced by the dealer and had codes P2106 & P2110.

http://www.aveoforum.com/forum/f108/p2a01-15776/

[Blue07]

Did you find out why your Aveo had all those codes? I changed the downstream sensor on mine and got 5 new codes: P0068, P2106, P2110, P2188, P161B. I'm thinking it might be a similar problem and solution. Thanks.

[avguy]

When posting a problem you need to give the full recent history. How did it run before the new sensor and also what codes were you getting then? How is it running now? Also the year, mileage, and list of any other recent repairs.

[Blue07]

When posting a problem you need to give the full recent history. How did it run before the new sensor and also what codes were you getting then? How is it running now? Also the year, mileage, and list of any other recent repairs.

Had code for downstream oxygen sensor p0137 and system too rich p0172. Replaced the o2 sensor but now I have P0068, P2106, P2110, P2188 and P161B. I took a video of the first start up after the replacement which can be viewed here Aveo check engine - YouTube
When I start the car on a cold morning the problem seems to be worse, it's better on a hot day. The first cold start up after I replaced the o2 sensor was terrible and the car wouldn't accelerate past 45mph with the accelerator to the floor. I turned off the car and started it up again and the problem went away, or so I thought. It does surge at times and now turning off the car will not make the car exceed 45mph. If you an see on the video the rpms go very low at times and now the car stalls if it drops too much.I had the battery checked and it is good, spark plugs and cables replaced in March 2014 but they were full of oil. Went ahead and had the gasket cover replaced in March. I replaced the engine oil, filter and air filter about 2,000 miles ago. Cleaned the throttle body today but noticed the butterfly will not open with the accelerator depressed. I could have sworn I had opened it up with the gas pedal before. I disconnected the negative battery cable to see if that would help and the problem keeps coming back. Anyways any help would be greatly appreciated. My car is a 2007 Chevy Aveo Ls with 120,000 miles on it.

[avguy]

It sounds like it was running too rich, and still is. You could try to confirm that by pulling the plugs when it stalls or is running really bad (one or more should be wet or damp with gas). A good first step would be checking all the vaccum lines for a crack - the small map sensor tube has been the problem for others in the past, but it could be another one as well. If you can't find anything by eye, I would do a smoke test next, if you can DIY or get one done for a decent price. If no vaccum leak is found, some of the other possibilities are the upstream O2 sensor, stuck fuel injector, and the TPS (which I think in '07 means a new throttle body).

[Blue07]

I can't believe it was the dirty throttle body again, 2nd time cleaning it this year. It could have been the plastic where the air filter sits was not connected to the hose below or a new clamp that I installed on a different hose but the engine light hasn't come back on. Thanks for all the help. `